There is no "legal consent" at the age of 14, but the girl's "actual consent" is relevant. If she hadn't consented, the original charges would've most likely been rape. So, I guess, there was a "relationship" in a sense...just an illegal one, obviously.

13 years old or younger: there is no "legal consent" or "actual consent," regardless of the circumstances. Sex = rape. KSA 21-3502(a)(2)

14 - 15 years old: there is no "legal consent," but their can be "actual consent." non-consensual = rape, consensual = agg indecent liberties. KSA 21-3504(a)(1)

"After all, all that must be proven is that the act" - you're right...that's not exactly what I intended to say. I'm not really trying to make an argument convincing you of my point of view, though, but rather simply state a fact and then give my own opinion to which we very well may disagree. Let me try to do a better job explaining.

The fact is: The jury was instructed on 2nd degree murder. You don't need to prove the actual cause of death to prove 2nd degree murder (or 1st degree murder). On a side note, you don't even have to find the body to prove murder. You can prove a murder with motive, opportunity, circumstantial evidence of the killing, and circumstantial evidence showing consciousness of guilt. For example, there are many cases of murder convictions where the victim's body has been burned/charred to such an extent that there is no way to actually know how that person was killed. Motive, opportunity, and circumstantial evidence can still support convictions in those cases.

The prosecution should have still sought to prove their alleged exact cause of death (chloroform followed by duct tape), but then stressed to the jury that they don't need to know the exact cause of death. All that they need to believe is that some criminal act of Casey's was responsible for Caylee's death, and that her criminal act was "dangerous to another and demonstrating a depraved mind without regard for human life."

Now my opinion: The lack of opportunity for anyone else but Casey to commit the crime, the circumstantial evidence tying her to caylee's death, and the evidence of her consciousness of guilt all show beyond a reasonable doubt that she murdered Caylee. IMO, she should've been found guilty of 2nd degree murder.